How do you follow up Heath Ledger's show-stopping performance in The Dark Knight? Many people think bringing in the Riddler is the way to go. And now there are more serious rumors that Inception's Joseph Gordon-Levitt could be on board.

First Showing is reporting from an inside source that not only is Chris Nolan's new villain in his next, and last, Batman film going to be the Riddler, but that fan favorite Joseph Gordon-Levitt is interested in the role.

But it's a bit more complicated than that. The source isn't indicating that the Riddler is the only, or main, villain. Plus, this isn't coming directly from a source close to JGL — but rather, from a casting grid supposedly leaked from the studio, which lists him as "interested." But hey, that's more slight confirmation than we've read on any Nolan Batman rumors. So take it with a major grain of salt, as with all such rumors.

The one thing this actor doesn't have going for him is his relative youth — since the age range on the casting grid for The Riddler was listed as 35 to 45. But after Inception's reality-warping stunts, aging JGL by half a dozen years would be child's play.